Advanced Materials Research Vols. 622-623

Abstract: AE 42 is rare earth containing magnesium alloy which was developed for creep resistance and automobile applications. This alloy was subjected to friction stir processing and the effect of processing parameters on the properties was studied in detail. Mechanical and metallurgical properties of stir zone were evaluated and compared with parent metal. Thermal cycling of stir zone was carried out to study the stability of it at high temperature. Due to processing, stir zone microstructure was refined to 5 micron. The second phase inter-metallic particles Mg₁₇Al₁₂, Al₁₁Ce₃ and A_l2Ce were refined to tiny pieces of 1-2 micron and evenly distributed in the matrix. The stir zone was stable up to 250°C during thermal cycling. Mechanical properties of friction stir zone were superior to parent metal.

Abstract: Electrical Discharge Machining (EDM) in Malaysia is widely used in mould making industries. Parts for automotive, defence and telecommunication industries are also other examples of the products produced. The process is based on removing material from a part by a series of repeated electrical discharges between a tool called electrode and the work piece with the presence of dielectric. The dielectric serves as transportation of removed particles, remains electrically non-conducting until the breakdown voltage is reached, reconditions the dielectric strength, increases the energy density in plasma channel and cools the electrode. This paper presents the machining of ASSAB 718HH work pieces with copper tool using EDM die sinking method. Three commercial EDM dielectrics; Kerosene, Novis and Amoil were tested and comparison between material removal rate (MRR), tool wear ratio (TWR) and surface finish (SF) are given. Through Pugh Method, result shows that ASSAB 718HH is best machined with Novis.

Abstract: This paper presents a postprocessor for five-axis milling machine that capable of converting CL (cutter location) data to machine control data (NC program). The proposed postprocessor method is based on inverse kinematics transformation and postprocessor module is programmed in Visual Basic language. The Deckel Maho DMU 50 _eVoluion five-axis machine with two rotary axes (B and C) on the table is modeled and verified in software VERICUT^® to validate the NC data generated by proposed postprocessor.

Abstract: Selective laser sintering (SLS) / melting (SLM) is a manufacturing technique which holds a very special place in the layer manufacturing process due to its widest range of material processing capability which no other technique can offer. It can process metals, rubber, composites, polymers and ceramics etc. As laser sintering technique is emerging as an advanced manufacturing technique, it is importance to study the phenomenon which affect the fabrication process, hence a study is undertaken to simulate the physical phenomenon such as laser absorption and Marangoni effect. By studying these phenomena, a much better control of the physical processes is possible during the laser sintering process of commercially pure titanium grade 2.

Abstract: This work aimed to prepare the bio-oil with low oxygen content via two-step process involving pyrolysis and catalytic deoxygenation. The raw bio-oil was produced from the pyrolysis of oil palm shell in a screw pyrolyzer with a heating rate of 25°C/min. Then, 10 ml of obtained bio-oil with 54.5 % (w/w) of oxygen content was upgraded by catalytic deoxygenation carried out in a fixed-bed reactor containing 20 g of NiMoS/-Al2O3 catalyst under nitrogen atmosphere. When the temperature in the reactor reached to the target point, the bio-oil was dropped by using a syringe pump at a constant flow rate of 0.2 ml/min. The results indicated that this process was efficient to reduce the oxygen content in the bio-oil to 11.5% (w/w) when the reaction temperature was 500°C

Abstract: Application of Design for Manufacturing (DFM) and Design for Assembly (DFA) methodologies can be beneficial to industries involved in the design and development of products. Improper design decisions are responsible for higher manufacturing cost for a product. Thus it is important to include DFMA by combining principles of both DFM and DFA principle early in the design process. This paper presents a case study of manufacture and assembly costs estimation during the design phase of washing machine and which is to be manufactured in company located in India, and intends to make this economically feasible. Solidworks and Solidview software tool were used to generate CAD models which were further analysed using DFMA software tool. The result obtained was accepted by industry and match with the market value of washing machine.

Abstract: Quantum-dot cellular automata (QCA) is an emerging nanotechnology that promises faster speed, smaller size, and lower power consumption compared to the transistor-based technology. Moreover, XOR is a useful component for the design of many logical and functional circuits. This paper proposes a novel and efficient QCA XOR design. The proposed XOR design has been compared to a few recent designs in terms of area, speed and complexity. Comparison of results illustrates significant improvements in our design as compared to traditional approaches. Also simulation proves that the proposed XOR design is completely robust and more sustainable to high input frequency as compared to other designs. This robustness is highly significant when this component is applied for realizing larger designs.

Abstract: Different mole ratios of sebacic acid (SA) and 1,6-bis(p-carboxyphenoxy) hexane (CPH) were used to make copolymer. g-HAP, hydroxyapatite (HAP) nanopowder surface-modified by polycaprolactone (PCL), was added with the copolymer to enhance the mechanical strength. Because of surface erosion, polyanhydride sustained the mechanical properties with time. The degradation of copolymer did not cause obvious decline in pH, and was thus less harmful to the osseous tissue. HAP is the main components of human bone and a good osteoinductive substance to help bone mineralization. The result of our study showed that CPH:SA = 7:3 added with10 wt% g-HAP was the best condition with maximum compress strength of 103 MPa. With slow degradation rate and durable mechanical strength, the novel biomaterial was suitable bone repair in future clinical application.

Abstract: Novel combined electrochemical and chemical synthesis methods for the preparation of Polypyrrole-based actuators are presented. Polypyrrole (PPy) actuators were electrochemically synthesized and after coating with a thin gold nano-layer, prepared into a Polyethersulfone (PI) substrate. Scanning Tunneling Microscopy (STM) and a potentiostat–galvanostat were used to confirm the actuation of PPy based actuators during the redox process. Three-layer actuator based on polypyrrole as electroactive material, Polyethersulfone as substrate and gold nanolayer in our proposed method have been realized. The structure strength and layer adhesion have been improved. This advancement in conducting polymer actuator technology will impact many engineering fields, where a stable, lightweight and large displacement actuator is needed.

Abstract: A type of new environmentally friendly lube additive----boron-nitrogen containing modified soybean oil was synthesized and characterized by infrared spectrum. Its tribological properties in rapeseed oil were tested on the four balls tester. The morphographies and tribochemical species of the worn surfaces were analyzed by means of Scanning Electron Microscope (SEM) and X--ray Photoelectron Spectroscope (XPS). The results show that the type of modified soybean oil as additives can obviously increase the load-carrying capacity 、anti-wear and friction-reducing abilities of rapeseed oil. Its lubrication mechanism is inferred that a high strength adsorption film and/or tribochemistry reaction film on the worn surface of the Al alloy due the carrier effect of a long chain rapeseed oil, high reaction activities of nitrogen, electron-deficient of boron and their synergisms.